Since 1993 the Transportation Research Committee of the Japanese Rocket Society (JRS) has been conducting a conceptual design study of a vertical takeoff and landing, fully reusable Single-Stage-to-Orbit (SSTO) rocket space tour vehicle for low Earth orbit operation. The vehicle is now called "Kankoh-maru" after the first modern western style steam-ship introduced to Japan in the Edo-era about 140 years ago.

The JRS Study Program is now in its third phase, studying design requirements and standards for technical certification of space tour vehicles. The committee has first reviewed the existing Japanese aviation regulations applied to passenger aircraft and helicopters approved by the civil aviation bureau of the Japanese Ministry of Transportation. The surveyed issues are flight characteristics, strength, structure, propulsion, equipment and operation.

There are many issues to be reconsidered and added for an orbital vehicle operated with rocket propulsion. The takeoff and landing procedure is one of the critical items that is very different from that of aircraft and helicopters in the matter of abort capability. The vehicle design must also take the specific environmental conditions into account, such as orbital temperature, vacuum, meteoroid, space radiation, cryogenic temperature of propellants and aerodynamic heating during reenty, in order to protect passengers and ground safety.

The safety standards for the new concept of "spaceworthiness" will play an important role for manufacturers supplying commercial space tour vehicles. This activity of the JRS is unique and is expected to promote space commercialization.